Jammer

Definition - What does Jammer mean?

In mobile computing, a jammer is a mobile communications device that transmits on the same frequency range as a cellphone to create strong cell tower interference and block cellphone signals and call transmission.

Jammers are usually undetectable, and users may experience minimal effects such as poor signal reception. Jamming devices may be used in any location but are typically deployed where cellphone use may be disruptive, such as in libraries and restaurants.

Techopedia explains Jammer

A working cellphone must be in constant communication with its network provider via a cell tower or base station. By sending out radio waves in cellphone frequencies, jammers launch denial-of-service attacks (DoS), causing mobile devices to lose base station communication.

Jammers come in a variety of shapes and sizes, including:

Portable and compact devices, like mobile phones

Box-shaped units that are similar to routers

Larger and far-reaching briefcase-style format

All jamming device types have three main parts, as follows:

An antenna to connect the device

A power supply or battery

Circuitry, which includes a voltage-controlled oscillator, tuning circuit, noise generator and radio frequency (RF) amplification

Handheld jammers are capable of disrupting signals within nine to 30 meters, while more powerful jammers create a huge bubble stretching as far as a mile or 1.6 kilometers.

In many countries, jammers are illegal, except in the military, law enforcement and other government agencies, where jammers are largely used to prevent bomb detonation or to isolate suspects in hostage situations.